Fixed crashes in QGLTextureDestroyer.

QGLTextureDestroyer will try to make the context current on the GUI
thread, regardless of whether it is owned by another thread. Use
QOpenGLSharedResourceGuard instead which does the right thing and takes
shared contexts into account.

Task-number: QTBUG-31403
Change-Id: I1377f9284995a7ba5af32c85296eef152fc035c8
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>

2 files changed, 7 insertions, 19 deletions

diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 72c6e035d9..3f496a4ffc 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -1579,10 +1579,7 @@ QGLContextPrivate::QGLContextPrivate(QGLContext *context)
 {
     group = new QGLContextGroup(context);
 
-    if (qApp) {
-        texture_destroyer = new QGLTextureDestroyer;
-        texture_destroyer->moveToThread(qApp->thread());
-    }
+    texture_destroyer = new QGLTextureDestroyer;
 }
 
 QGLContextPrivate::~QGLContextPrivate()
diff --git a/src/opengl/qgl_p.h b/src/opengl/qgl_p.h
index ff9baf8971..484c3ea2d9 100644
--- a/src/opengl/qgl_p.h
+++ b/src/opengl/qgl_p.h
@@ -335,25 +335,16 @@ QT_END_NAMESPACE
 Q_DECLARE_METATYPE(GLuint)
 QT_BEGIN_NAMESPACE
 
-class Q_OPENGL_EXPORT QGLTextureDestroyer : public QObject
+class Q_OPENGL_EXPORT QGLTextureDestroyer
 {
-    Q_OBJECT
 public:
-    QGLTextureDestroyer() : QObject() {
-        connect(this, SIGNAL(freeTexture(QGLContext *, QPlatformPixmap *, quint32)),
-                this, SLOT(freeTexture_slot(QGLContext *, QPlatformPixmap *, quint32)));
-    }
-    void emitFreeTexture(QGLContext *context, QPlatformPixmap *boundPixmap, GLuint id) {
-        emit freeTexture(context, boundPixmap, id);
+    void emitFreeTexture(QGLContext *context, QPlatformPixmap *, GLuint id) {
+        if (context->contextHandle())
+            (new QOpenGLSharedResourceGuard(context->contextHandle(), id, freeTextureFunc))->free();
     }
 
-Q_SIGNALS:
-    void freeTexture(QGLContext *context, QPlatformPixmap *boundPixmap, quint32 id);
-
-private slots:
-    void freeTexture_slot(QGLContext *context, QPlatformPixmap *boundPixmap, quint32 id) {
-        Q_UNUSED(boundPixmap);
-        QGLShareContextScope scope(context);
+private:
+    static void freeTextureFunc(QOpenGLFunctions *, GLuint id) {
         glDeleteTextures(1, &id);
     }
 };